Insulin receptor substrate
An important protein in insulin signalling, Insulin Receptor Substrate, IRS, has at least 4 different isoforms. For many years it was known as pp180 or pp185 as it was just seen as a 180-185 kDa band on a gel, and its function was unknown.
Once the insulin receptor has been activated, the β subunit of the insulin receptor phosphorylates the tyrosine residues on IRS. Once phosphorylated, the IRS becomes a docking protein for proteins that contain SH2 domains. The IRS protein contains phosphotyrosine binding (PTB) and PH domain. IRS binds to the PI3K arm of insulin signalling, and the Grb2 arm, as well as other proteins containing SH2 domains including, Syp and Nck.
- ↑ S. Whelan, W. Dias, L Thiruneelakantapillai, M. Lane, G. Hart. (2010) 'Regulation of insulin receptor substrate 1 (IRS-1)/AKT kinase-mediated insulin signaling by O-Linked beta-N-acetylglucosamine in 3T3-L1 adipocytes', J Biol Chem, 285(8):5204-11.